1. Field of the Invention
This invention relates to an apparatus and method for preventing ice from forming on a cooling system, and more particularly to an apparatus and method for preventing condensed water from forming ice on evaporator coils of a refrigeration system on a power generating system.
2. Description of Related Art
The combustion gas turbine has long been used and very highly developed to generate power in electric power plants by burning natural gas, or other gaseous hydrocarbon fuels. The thermal efficiency, however, of such turbines is not very high and limited to values of the order of about 38% because all the heat of combustion has not been utilized fully.
To increase the efficiency of turbines it is known to refrigerate the air entering the gas turbine to temperatures well below ambient temperatures, such as about -60.degree. F. See "The Refrigerated Gas and Vapor Turbine Cycle", J. H. Anderson (1982).
By refrigerating the air prior to entering the air compressor, the density of the air is greatly increased. Therefore, the mass flow is increased and much more fuel can be burned to raise the gas temperature to the acceptable high combustion temperature of 2000.degree. F. or higher. This results in significantly higher power output from the gas turbine.
However, when cooling air to temperatures below the freezing point of water, condensed water forms ice on the evaporator coils of a refrigeration system which significantly impedes the flow of air through the evaporator coils. Typically, the refrigeration system must be shut down to remove the ice formed on the evaporator coils.
It has been known to add an antifreeze solution to the air passing through the refrigeration system to prevent ice from forming on the evaporator coils. In conventional refrigeration systems, when an antifreeze solution is used to prevent water freezing on evaporator coils a special means must be used to recover the antifreeze because it becomes diluted with the condensed water.
An object of the present invention is to solve the problems associated with conventional methods of preventing ice from forming on a refrigeration system.